Various snap models are known. Some are formed from several components which may be made of different materials and assembled after manufacture. This design requires a certain assembly time and, depending on the materials used, the weight of the snap may be variable and substantial, especially when metal is used. In addition, if the tongue is metal and depending on its thickness, the user runs the risk of injury. This thickness is chosen so as to provide strength and elasticity. When metal is used and in order to provide properties ensuring elasticity and tension, the tongue is thin and thus has a sharp edge. Furthermore, depending on the particular use, there is a high risk of corrosion when the snap is partially or completely metallic.
Conventional practice also includes the manufacture of a type of snap molded from a single piece of plastic. Its mold joint is located on the upper surface of the upper part of its body, this surface being parallel to the median horizontal plane of this body. Thus, this kind of snap and its formation mold do not make it possible to obtain a smooth surface on the upper face of its body, thereby depriving it of an aesthetic appearance for some uses. Furthermore, this mode of production does not allow recessed or relief markings obtained from partially or completely closed impressions on this same upper surface. Similarly, the markings deriving from each of the half-parts of the mold will be produced with molding displacements or offsets.